Experimentally Manipulated Bias in School Psychologists' Scoring of WISC-III Protocols.

Sherman, Lawrence W.; Taylor, Amy N.

Experimenter bias effects were experimentally manipulated in a sample of 97 school psychologists scoring 3 subscales (Similarity, Vocabulary, and Comprehension) of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III). First year (n=29), interns (n=42), and experienced (n=26) psychologists were randomly assigned to either a bias or control group and requested to score the same 3 subscale protocols. The study focused on the effects of an experimentally induced bias effect, Down Syndrome, of the subject given the WISC-III. No statistically significant interactions between experimental groups (biased and control) and level of experience were obtained. All main effects were non-significant. There results are interpreted as an affirmation of the objectivity of scoring for these relatively subjective subscales, as well as the quality of training of these students, interns, and experienced practitioners. (Contains 4 tables and 20 references.) (Author/SLD)